JPH0628562U - Refrigeration equipment - Google Patents

Abstract

(57) [Abstract] [Purpose] To prevent the refrigerant condensed by defrost from staying in the cooling coil and shorten the defrost time. [Composition] A compressor 1, a condenser 2, an expansion valve 4, a distributor 9 and a cooling coil constitute a refrigeration circuit, and the compressor 1
An electromagnetic valve 12 that is closed during the cooling operation but is opened during the defrosting operation is provided in the hot gas pipe 13 that connects the discharge side of the cooling coil to the cooling coil, and the outlet 8 of the cooling coil is connected to the suction side of the compressor 1. In a refrigerating apparatus having a suction pipe electromagnetic valve 14 that is opened during a cooling operation but is closed during a defrosting operation, in the suction pipe 1B connected to the re-evaporator 11 in parallel with the solenoid valve 14. A refrigerant reservoir 10 is provided between the outlet 8 of the cooling coil and the inlet of the re-evaporator 11 in the suction pipe 1B.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a refrigerating device for defrosting a cooling coil by a hot gas method, which is used for air conditioning in a cold store or a building.

[0002]

[Prior art]

 Figure 2 shows a system diagram of a conventional refrigeration system that uses a hot gas system to defrost the cooling coil. During the cooling operation, the defrost solenoid valve 12 of the hot gas pipe 13 is closed, while the solenoid valve 14 of the suction pipe 1B is open, and the refrigerant from the compressor 1 is sent to the condenser 2 through the discharge pipe 1A. The refrigerant liquefied in the condenser 2 is temporarily stored in the liquid receiver 3, then the pressure is lowered by the expansion valve 4, and the cooling coil in the cooler 5 is passed from the distributor 9 through the narrow tube 9a. Sent to.

The refrigerant takes heat from the surroundings in the cooling coil, and is sucked into the compressor 1 again through the suction pipe 1B connected to the outlet header 8 of the cooling coil. The cooling operation is performed by repeating this refrigeration cycle.

On the other hand, during the defrosting operation, the defrosting electromagnetic valve 12 of the hot gas pipe 13 is opened by a defrosting command from a timer or the like, while the electromagnetic valve 14 of the suction pipe 1B is closed and discharged from the compressor 1. The high-temperature refrigerant gas (hot gas) is sent to the cooling coil in the cooler 5 via the drain pan coil 6 provided in the drain pan 7, and the frost attached to the outer surface of the cooling coil is melted by the heat of the hot gas.

The hot gas that has been defrosted is condensed by being deprived of heat by the frost, and is sent to the re-evaporator 11 that is provided in parallel across the solenoid valve 14 of the suction pipe 1B that is closed during the defrosting operation. It is then gasified by exchanging heat with cooling water and air, and is again sucked into the compressor 1 from the suction pipe. Reference numeral 15 in the figure is a pressure adjusting valve for sending the condensed refrigerant to the re-evaporator at a predetermined pressure.

The water that has flown down from the outer surface of the cooling coil due to defrosting is received by the drain pan 7 that has been heated by the drain pan coil 6, and is discharged to the outside.

[0007]

[Problems to be solved by the device]

 While hot gas is sent to the cooling coil during defrosting operation, the frost-melting cold water drips from the cooling coil on the upper side of the cooling coil on the lower side of the cooler, so defrosting is higher than that on the cooling coil on the upper side. However, hot gas is wastefully supplied into the upper cooling coil that has been defrosted before the defrosting of the lower cooling coil is completed.

On the other hand, the cooling coil on the lower side has a lower temperature than the cooling coil on the upper side due to the molten water of frost, so that the amount of condensed refrigerant is larger than that of the upper side cooling coil and it is easy to accumulate. The accumulated condensed refrigerant hindered the supply of hot gas and reduced the defrosting efficiency of the cooling coil on the lower side. Also, the refrigerant condensed by defrost is sent from the suction pipe to the re-evaporator, but when the amount of condensed refrigerant increases, this refrigerant accumulates in the suction pipe and the cooling coil, and in the cooling coil, especially in the lower side cooling. It was trapped in the coil, making it difficult for hot gas to flow.

An object of the present invention is to prevent the refrigerant condensed by defrost from staying in the cooling coil and shorten the defrost time.

[0010]

[Means for Solving the Problems]

 In order to solve such a problem, the refrigerating apparatus according to the present invention constitutes a refrigerating circuit by a compressor, a condenser, an expansion valve, a distributor and a cooling coil, and connects the discharge side of the compressor to the cooling coil. The hot gas pipe is closed during the cooling operation, but is equipped with a solenoid valve that is opened during the defrosting operation, and the suction pipe that connects the outlet of the cooling coil to the suction side of the compressor is open during the cooling operation. In a refrigeration system equipped with a suction valve solenoid valve that is closed during defrosting operation and a re-evaporator installed in parallel with this solenoid valve, the cooling coil outlet and re-evaporator inlet of the suction pipe are A refrigerant pool is provided between the two.

[0011]

[Action]

 The refrigerant condensed in the cooling coil during the defrosting operation is discharged to the refrigerant pool, where it is once stored and then sent to the re-evaporator sequentially. Therefore, the condensed refrigerant does not stay in the cooling coil on the lower side of the cooler, and the hot gas is supplied to the cooling coil inside the cooler without any problem, improving the defrosting efficiency and defrosting time. Shortened.

[0012]

【Example】

 Hereinafter, a specific embodiment of the refrigerating apparatus according to the present invention will be described in detail with reference to the system diagram shown in FIG. In the description, the same parts as those in the conventional example are designated by the same reference numerals, and a part of the description of the overlapping parts will be omitted.

A discharge pipe 1 A from the compressor 1 is connected to an expansion valve 4 via a condenser 2 and a liquid receiver 3. A distributor 9 is connected to the expansion valve 4, the distributor is connected to a cooling coil in the cooler 5 by a thin tube 9a, and an outlet header 8 of the cooling coil is connected to a suction pipe 1B of the compressor 1. . The suction pipe 1B is connected to the suction side of the compressor 1 via a refrigerant reservoir 10 and a solenoid valve 14 for temporarily storing condensed refrigerant discharged from the cooling coil during defrosting, and the solenoid valve 14 is used during cooling operation. It is open, but it is closed during defrosting operation.

The suction pipe 1B is provided with a side passage that straddles the solenoid valve 14, and a re-evaporator 11 is provided in this side passage. The condensed refrigerant flowing into the re-evaporator 11 from the cooling coil during the defrosting operation is , Is heat-exchanged with water and air supplied to the re-evaporator to be gasified. A hot gas pipe 13 for defrosting branches from the discharge pipe 1A of the compressor 1, and the hot gas pipe is closed during the cooling operation but is opened during the defrosting operation. The defrost electromagnetic valve 12 and the drain pan coil 6 are provided. It is connected to the distributor 9 via.

Next, the operation of the refrigerating apparatus configured as described above will be described. During the cooling operation, the defrost electromagnetic valve 12 is closed, but the electromagnetic valve 14 of the suction pipe is opened, and the refrigerant flows from the compressor 1 to the condenser 2, the liquid receiver 3, the expansion valve 4, the distributor 9, and the cooler 5. The refrigeration circuit configured as described above circulates as shown by the solid line in the figure.

On the other hand, during the defrosting operation, the defrost electromagnetic valve 12 is opened by a defrosting command from a timer or the like, whereas the electromagnetic valve 14 of the suction pipe is closed, and the hot gas discharged from the compressor 1 is discharged from the discharge pipe 1A. The drain pan coil 6 connected to the hot gas pipe 13 branched from the above heats the drain pan 7 and sends it to the cooling coil in the cooler 5, where it is condensed by melting the frost adhering to the outside of the cooling coil. It becomes a liquid refrigerant.

The liquefied refrigerant passes through the outlet header 8 of the cooling coil, is temporarily stored in the cooling medium reservoir 10 provided in the suction pipe 1B, and is sent from the pressure regulating valve 15 to the re-evaporator 11 at a predetermined pressure. Is gasified by being heat-exchanged with the cooling water and the air, and is again sucked into the compressor 1 through the suction pipe 1B. At this time, the refrigerant condensed in the cooling coil in the cooler 5 is temporarily stored in the refrigerant pool 10 and therefore does not collect in the suction pipe 1B and the cooling coil and does not hinder the flow of hot gas. The capacity of the refrigerant reservoir 10 is determined according to the amount of refrigerant condensed in the cooling coil during the defrosting operation.

[0018]

[Effect of device]

 According to the present invention, since the refrigerant condensed in the cooling coil during the defrosting operation is temporarily stored in the refrigerant pool, the condensed refrigerant does not stay in the suction pipe and the cooling coil. Therefore, the hot gas is supplied to the cooling coils on the upper and lower sides of the cooler without any trouble, and the defrosting failure is prevented.The defrosting can be performed more efficiently than before, and the entire cooling coil is removed. The frost time can be shortened to save energy.

[Brief description of drawings]

FIG. 1 is a system diagram showing an embodiment of the present invention.

FIG. 2 is a system diagram showing a conventional example.

[Explanation of symbols]

 1 Compressor 1A Discharge pipe 1B Suction pipe 2 Condenser 3 Liquid receiver 4 Expansion valve 5 Cooler 6 Drain pan coil 7 Drain pan 8 Outlet header 9 Distributor 9a Capillary pipe 10 Refrigerant pool 11 Re-evaporator 12, 14 Solenoid valve 13 Hot gas Tube 15 Pressure control valve

Claims (1)

[Scope of utility model registration request] 1. A compressor, a condenser, an expansion valve, a distributor and a cooling coil constitute a refrigeration circuit, and a hot gas pipe connecting the discharge side of the compressor to the cooling coil is closed during a cooling operation. , Equipped with a solenoid valve that is opened during defrosting operation, and for the suction pipe that is open during cooling operation on the suction pipe that connects the outlet of the cooling coil to the suction side of the compressor, but is closed during defrosting operation A refrigeration system comprising a solenoid valve and a re-evaporator provided in parallel across the solenoid valve, wherein a refrigeration pool is provided between the outlet of the cooling coil and the re-evaporator inlet of the suction pipe.